SEMICONDUCTOR DEVICE AND DISPLAY APPARATUS

• US 20110062441A1
• Filed: 05/11/2009
• Published: 03/17/2011
• Est. Priority Date: 05/12/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yabuta, Hisato, Kawasaki, Takehiko, Ofuji, Masato, Hayashi, Ryo, Takai, Yasuyoshi, Kaneko, Norio
• Granted Patent: US 8,513,662 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 29/78633 with a light shield
• CPC Class Codes: H01L 29/78645 with multiple gate

Abstract

Provided is a semiconductor device including a semiconductor element including at least a semiconductor as a component characterized by including: a mechanism for irradiating the semiconductor with light having a wavelength longer than an absorption edge wavelength of the semiconductor; and a dimming mechanism, provided in a part of an optical path through which the light passes, for adjusting at least one factor selected from an intensity, irradiation time and the wavelength of the light, wherein a threshold voltage of the semiconductor element is varied by the light adjusted by the dimming mechanism.

Claims

1. A semiconductor device including a semiconductor element including at least a semiconductor as a component, the semiconductor device comprising:

a mechanism for irradiating the semiconductor with light having a wavelength longer than an absorption edge wavelength of the semiconductor; and

a dimming mechanism, provided in a part of an optical path through which the light passes, for adjusting at least one selected from the intensity, irradiation time and wavelength of the light, wherein

a threshold voltage of the semiconductor element is varied by the light adjusted by the dimming mechanism.

2. The semiconductor device according to claim 1, wherein the dimming mechanism absorbs or blocks light with a wavelength shorter than the absorption edge wavelength of the semiconductor.

3. The semiconductor device according to claim 1, wherein the dimming mechanism is provided between a light source for light irradiation and the semiconductor.

4. The semiconductor device according to claim 1, where the dimming mechanism includes one element selected from a liquid-crystal element, an electrochromic element, a color filter and an electro-optic effect element.

5. The semiconductor device according to claim 1, wherein the dimming mechanism detects a variation in the threshold voltage of the semiconductor element, and adjusts the light based on the detected variation.

6. The semiconductor device according to claim 1, wherein the light irradiation is performed before driving of the semiconductor device.

7. The semiconductor device according to claim 1, wherein the light irradiation is performed during driving of the semiconductor device or after termination of the driving.

8. The semiconductor device according to claim 1, where the semiconductor element includes at least a gate electrode, a source electrode, a drain electrode, a channel layer and a gate insulation film;

and the semiconductor is the channel layer.

9. The semiconductor device according to claim 1, wherein a surface density of in-gap states in the semiconductor is no more than 10¹³ cm⁻

2 eV<sup>−

1</sup>.

10. The semiconductor device according to claim 1, wherein the semiconductor is a semiconductor with a band gap of no less than 1.55 eV.

11. The semiconductor device according to claim 1, wherein the semiconductor is of amorphous In—

Ga—

Zn—

O (IGZO), amorphous In—

Zn—

O (IZO) or amorphous Zn—

Sn—

O (ZTO).

12. The semiconductor device according to claim 11, wherein the semiconductor contains at least one type of element selected from elements belonging to groups I to XIV in the periodic table, and antimony and bismuth;

and a number of oxygen atoms equal to or exceeding a total number of atoms for the element.

13. A display apparatus characterized by using a semiconductor device according to claim 1 for a drive element for the display apparatus.

14. The display apparatus according to claim 13, wherein the display apparatus is an image display apparatus including a backlight light source, and the mechanism for irradiating the semiconductor with light having a wavelength longer than an absorption edge wavelength of the semiconductor is the backlight light source.

15. The display apparatus according to claim 13, wherein the semiconductor element is a thin-film transistor, the thin-film transistor is connected to a mechanism for detecting a TFT characteristic of the thin-film transistor, and the dimming mechanism adjusts the light based on the TFT characteristic detected by the mechanism for detecting a TFT characteristic.

16. The display apparatus according to claim 14, wherein the semiconductor element is a thin-film transistor, the thin-film transistor is connected to a mechanism for detecting a TFT characteristic of the thin-film transistor, and the dimming mechanism adjusts the light based on the TFT characteristic detected by the mechanism for detecting a TFT characteristic.

17. The semiconductor device according to claim 1, wherein the semiconductor contain at least one element selected from In, Ga, Zn, and Sn.

18. The semiconductor device according to claim 2, wherein the dimming mechanism is provided between a light source for light irradiation and the semiconductor.

19. The semiconductor device according to claim 18, wherein the dimming mechanism includes one element selected from a liquid-crystal element, an electrochromic element, a color filter and an electro-optic effect element.

20. The semiconductor device according to claim 2, wherein the dimming mechanism includes one element selected from a liquid-crystal element, an electrochromic element, a color filter and an electro-optic effect element.